Toxicology, Solid and Hazardous Waste Treatment Brian Kaestner Saint Mary’s Hall Thanks to Miller and Clements

Dose (hypothetical units) Number of individuals affected Toxicology DDT in fish-eating birds (ospreys) 25 ppm DDT in large fish (needle fish) 2 ppm DDT in small fish (minnows) 0.5 ppm DDT in zooplankton 0.04 ppm Toxicity Dosage Bioaccumulation DDT in water 0.000003 ppm, Or 3 ppm Biomagnification Very Sensitive Majority of population 20 40 60 80 Dose (hypothetical units) Number of individuals affected Synergism Acute effect Chronic effect

Poisons 100 75 50 2 4 6 8 10 12 14 16 Percentage of population killed by a given dose Dose (hypothetical units) LD Poison LD50 25

Chemical Hazards Hazardous chemicals Mutagens Teratogens Carcinogens Neurotoxins Precautionary principle

Wasting Resources Industrial and agricultural waste Municipal solid waste Burned in incinerators (16%) Dumped in landfills (54%) Recycled or composted (30%) US: 1,600 lb/person Mining and oil and gas production 75% Industry 9.5% Agriculture 13% Sewage sludge 1% Municipal 1.5%

Hazardous Wastes Contains one or more of 39 identified compounds Catches fire easily Reactive or explosive Corrodes metal containers

Producing Less Waste and Pollution Waste management (high waste approach) Burying, burning, shipping Waste prevention (low waste approach) Reduce, reuse, recycle Chemical or biological treatment Burial

Dealing with Materials Use and Wastes 1st Priority 2nd Priority Last Priority Primary Pollution and Waste Prevention • Change industrial process to eliminate use of harmful chemicals • Purchase different products • Use less of a harmful product • Reduce packaging and materials in products • Make products that last longer and are recyclable, reusable or easy to repair Secondary Pollution • Reduce products • Repair products • Recycle • Compost • Buy reusable and recyclable products Waste Management • Treat waste to reduce toxicity • Incinerate waste • Bury waste in landfill • Release waste into environment for dispersal or dilution Fig. 21.4, p. 521

Hazardous Waste Regulation in the United States Resource Conservation and Recovery Act Comprehensive Environmental Response, Compensation, and Liability Act Superfund National Priority List Polluter-pays principle

Dealing with Hazardous Wastes Produce Less Waste Convert to Less Hazardous or Nonhazardous Substances Put in Perpetual Storage Manipulate processes to eliminate or reduce production Recycle and reuse Land treatment Incineration Thermal Chemical physical, and biological Ocean and atmospheric assimilation Landfill Underground injection Waste piles Surface impoundments Salt formations Arid region unsaturated zone

Above Ground Hazardous Waste Disposal transporter Hazardous waste Support column Inspector Elevator shaft

Deep-well Disposal Advantages Safe method if sites are chosen carefully Wastes can be retrieved if problems develop Low cost Disadvantages Leaks or spills at surface Leaks from corrosion of well casing Existing fractures or earth quakes can allow wastes to escape into groundwater Encourages waste production

Municipal Waste

Sanitary Landfill Compacted solid waste Topsoil Sand Clay Garbage Synthetic liner Subsoil When landfill is full, layers of soil and clay seal in trash Methane storage and compressor building Electricity generator Leachate treatment system Methane gas recovery Pipe collect explosive methane gas used as fuel to generate electricity Compacted solid waste storage tanks monitoring well Groundwater Leachate pipes Leachate pumped up to storage tanks for safe disposal Clay and plastic lining to prevent leaks; pipes collect leachate from bottom of landfill

Advantages Disadvantages No open burning Little odor Low groundwater pollution if sited properly Can be built quickly Low operating costs Can handle large amounts of waste Filled land can be used for other purposes No shortage of landfill space in many areas Noise and traffic Dust Air pollution from toxic gases and volatile organic compounds release greenhouse gases (methane and CO2) Groundwater contamination Slow decomposition of wastes Encourages waste production Eventually leaks and can contaminate groundwater

Power plant Steam Smokestack Electricity Turbine Generator Crane Wet scrubber Boiler Electrostatic precipitator Furnace Conveyor Dirty water Water Bottom ash Fly ash Waste pit Conven- tional landfill Hazardous Waste landfill Waste treatment

Mass burn incineration Burning Wastes Mass burn incineration Advantages Reduced trash volume Less need for landfills Low water pollution Disadvantages High cost Air pollution (especially toxic dioxins) Produces a highly toxic ash Encourages waste production Air pollution Waste to energy

Reuse Extends resource supplies Reduces energy use Reusable shipping containers and grocery bags

Recycling Primary (closed-loop) Post consumer waste Aluminum can, used once Steel can used once Recycled steel can Glass drink bottle used once Recycled aluminum can Recycled glass drink bottle Refillable drink bottle, used 10 times 8 16 24 32 Energy (thousands of kilocalories) Primary (closed-loop) Post consumer waste

Characteristics of Recyclable Materials Easily isolated from other waste Available in large quantities Valuable

Benefits of Recycling Reduces global warming Reduces acid deposition Reduces urban air pollution Make fuel supplies last longer Reduces Saves energy energy demand water pollution Recycling Reduces solid waste disposal mineral demand Protects species habitat destruction Fig. 21.7, p. 530

Recycling in the US Centralized recycling of mixed waste (MRFs) Separated recycling Economic benefits Increasing recycling in the US

Case Studies: Recycling Aluminum, Wastepaper, and Plastics 40% of aluminum recycled in US Recycled aluminum uses over 90% fewer resources Paper: preconsumer vs. postconsumer recycling 10% or less of plastic recycled in US

Solutions: Achieving a Low-Waste Society Local grassroots action International ban on 12 persistent organic pollutants (the dirty dozen) Cleaner production